1. Field of the Invention
This invention relates to a method of waterproofing masonry walls by coating the inner surface with a one-package silicone elastomeric emulsion.
2. Description of the Prior Art
Materials, including certain silicone materials, have been applied to masonry walls to retard the absorption of water during rainstorms. These materials are useful because they meet the requirement for producing a treated surface which repels rain water running over its surface. Such water produces little pressure other than what might be provided by the wind. Many references refer to waterproofing walls when they are really referring to such a water repellent application.
Silicone materials used for such water repellent applications are not suitable for applications where the water is under a hydrostatic pressure, such as in a swimming pool or on a basement wall where there is a possibility of water resting against the wall and exerting a pressure differential between the inside and outside of the wall.
Kather and Torkelson in "Industrial and Engineering Chemistry," 46, 381-4 (1954), teach that silicones applied to concrete blocks are ineffective for waterproofing. In order to successfully waterproof a basement wall on the inner surface, they teach coating the blocks with two coats of cement paint, then coating the painted blocks with a 2 percent solution of sodium metasilicate. This treatment gave a waterproof surface which withstood a 4 foot head of water except for pinholes in the application. The pinholes had to be plugged to yield a useful waterproof surface. Similar results were obtained by adding sodium metasilicate to the cement paint before it was applied.
Hurst in British Pat. No. 848,352 teaches that walls, such as in basements, can be waterproofed by applying a coating comprising a mixture of water-soluble siliconate and a dispersion or emulsion of rubber latex in a cement, mortar, or plaster mix. His Example 3 shows such a mixture which he states can be applied to the inner surface of a wall by trowel or when diluted by a cement spraying machine. He gives no indication of the effectiveness of such a surface application.
Noll and Weisbach in an article on "Production and kind of action of molecular silicone films on materials of a silicate nature," Zement-Kalk-Gips 9, 476-86 (1956): CA 51, 9120c teach that emulsions are not a suitable treatment for waterproofing masonry because they do not penetrate as do solvent solutions.